Aug 1, 2020 04:15 AM
https://www.economist.com/science-and-te...ctric-cars
EXCERPTS: . . . As a marketing device, the million-mile battery will give electric-car buyers -- even those never likely to put a million miles on the clock -- more confidence that their batteries are robust. But some users might truly desire a lifetime range that great. [...] Contemporary Amperex Technology, a giant Chinese firm [...is...] ready to start manufacturing batteries which would last for 16 years or 2m kilometres. Elon Musk has hinted that Tesla ... has a million-mile battery in the works. ... And over in Detroit, General Motors (GM) is in the final stages of developing an advanced battery which it says has similar longevity.
“It’s a great catchphrase; the million-mile battery,” says George Crabtree [...] “But the fact you can drive a million miles may not be the most relevant parameter to look at.” Thrash a car and its battery will deteriorate faster. Regular fast-charging also reduces battery life, as do overcharging and deep discharging. Driving in extremely hot or cold weather does not help either. And battery life will diminish even if you just leave the car in the garage. The real point of a million-mile battery is that the technological advances required to make it possible will deal with these things as well.
[...] It is difficult to generalise about the extent to which these processes reduce a battery’s lifetime. Not only does it depend on how that battery is used, but also how it is made. Li-ion cells come in different forms and a variety of chemistries, some of which have not been around long enough in cars for people to know for sure how long they will last. Nor is there any independent testing, says Dr Crabtree.
Nevertheless, the industry has a few rules of thumb. Once a battery’s capacity falls below 80% of its starting value, it is generally thought no longer suitable for use in vehicles. Some reckon that, on average, Li-ion batteries lose 2% of their capacity a year. This may not seem much, but by the time a vehicle is six years old it could mean it is halfway through its useful life.
Battery technology is improving all the time. As a consequence, so are calendar and use-dependent lifetimes. [...] GM will be using these cathodes in a new battery, called Ultium, that it has developed in partnership with LG Chem, a South Korean firm. Ultium batteries, production of which is planned to start next year at a factory in Ohio, should provide electric cars with single-charge ranges of 650km or more. That compares with the 400km range which might these days reasonably be expected from a mid-size electric car. Asked if the Ultium is a million-mile battery, Tim Grewe [head of GM’s electrification strategy] replied, “Many customers could get that.” (MORE - details)
EXCERPTS: . . . As a marketing device, the million-mile battery will give electric-car buyers -- even those never likely to put a million miles on the clock -- more confidence that their batteries are robust. But some users might truly desire a lifetime range that great. [...] Contemporary Amperex Technology, a giant Chinese firm [...is...] ready to start manufacturing batteries which would last for 16 years or 2m kilometres. Elon Musk has hinted that Tesla ... has a million-mile battery in the works. ... And over in Detroit, General Motors (GM) is in the final stages of developing an advanced battery which it says has similar longevity.
“It’s a great catchphrase; the million-mile battery,” says George Crabtree [...] “But the fact you can drive a million miles may not be the most relevant parameter to look at.” Thrash a car and its battery will deteriorate faster. Regular fast-charging also reduces battery life, as do overcharging and deep discharging. Driving in extremely hot or cold weather does not help either. And battery life will diminish even if you just leave the car in the garage. The real point of a million-mile battery is that the technological advances required to make it possible will deal with these things as well.
[...] It is difficult to generalise about the extent to which these processes reduce a battery’s lifetime. Not only does it depend on how that battery is used, but also how it is made. Li-ion cells come in different forms and a variety of chemistries, some of which have not been around long enough in cars for people to know for sure how long they will last. Nor is there any independent testing, says Dr Crabtree.
Nevertheless, the industry has a few rules of thumb. Once a battery’s capacity falls below 80% of its starting value, it is generally thought no longer suitable for use in vehicles. Some reckon that, on average, Li-ion batteries lose 2% of their capacity a year. This may not seem much, but by the time a vehicle is six years old it could mean it is halfway through its useful life.
Battery technology is improving all the time. As a consequence, so are calendar and use-dependent lifetimes. [...] GM will be using these cathodes in a new battery, called Ultium, that it has developed in partnership with LG Chem, a South Korean firm. Ultium batteries, production of which is planned to start next year at a factory in Ohio, should provide electric cars with single-charge ranges of 650km or more. That compares with the 400km range which might these days reasonably be expected from a mid-size electric car. Asked if the Ultium is a million-mile battery, Tim Grewe [head of GM’s electrification strategy] replied, “Many customers could get that.” (MORE - details)